Balanced Ventilation in Multi-Family Homes

Simply Balanced Ventilation

We know that a healthy home starts with a ventilation system that brings in fresh air and controls the Indoor Air Quality (IAQ).

Balanced ventilation helps eliminate pollutants such as VOCs, pollen, and cooking odors while providing clean air, controlling humidity, and preventing mold.

We help you see what solution gets you clean air and why and where you might want to go beyond that to achieve a healthier design and ensure your occupants' health and comfort.

A fresh air appliance provides a controlled way of ventilating a multi-family dwelling without excessive energy losses. 

Photo of Bruno Poitras
Bruno Poitras
Regional Business Development Director - North America

Regulations and Factors

Important to know
  • ASHRAE 62.2 is a national standard that provides methods for achieving minimally acceptable indoor air quality (IAQ) for multi-family structures of more than three stories.

  • ASHRAE 90.1 is a national standard that describes the minimum requirements for energy-efficient design of most buildings, including multi-family construction.

  • 2021 IECC is an International Energy Conservation Code that addresses energy efficiency on several fronts including cost, energy usage, use of natural resources, and the impact of energy usage on the environment from most buildings

  • C403.7.4.1 Nontransient dwelling units Nontransient dwelling units shall be provided with outdoor air energy recovery ventilation systems with an enthalpy recovery ratio of not less than 50% at cooling design conditions and not less than 60% at heating design conditions

  • Exceptions Nontransient dwelling units in Climate Zone 3C. Nontransient dwelling units with not more than 500 sq.ft. of conditioned floor area in Climate Zones 0, 1, 2, 3, 4C, and 5C

Ideal Project Profile

Discovery Questions

Good to know

Does the National Code requirement apply in my jurisdiction?

Provisions of local Mechanical Codes and Energy Code in certain states require multi-family homes in buildings of four stories or more to have balanced ventilation with heat or energy recovery systems. Consult with your local Code. 

Are these products PHIUS or LEED-certified?

These products offer credits related to air quality improvement in new construction.

Is a higher latent recovery/moisture transfer a selling advantage?

In colder winter climates, the higher the recovery, the more moisture will be returned back with the supply air during the heating season. In humid summer climates, the conditioned air from indoors has a lower humidity level than outdoors so the higher the transfer level is the more moisture will be removed from the outdoor air that is being brought in.

How important is Total Recovery Efficiency?

The higher the percentage, the greater the comfort. For example, if the indoor room temperature is 70F and the outside temperature is 30F, the greater TRE rate could mean the difference between having air in the low 60s coming into the dwelling vs air that is over 65F.

What are Defrost Options?

Image of the defrost airflow on an ATMO

Supply Fan Shut-down

The supply air fan shuts down when the outdoor air temperature drops to 14F (-10C) or lower.  During the defrost cycle, the supply air fan (pulls the cold air into the appliance) shuts down.  

The exhaust air fan (pulls air from the indoors) switches to high speed maximizing defrost effectiveness.  


  • Simple and robust defrost prevention system.  

Image of the defrost airflow on a HERO


The motorized damper temporarily closes and blocks the incoming fresh air stream. The return air circulates through the core while defrosting it.  

The exhaust air fan shuts down while the supply air fan switches to high speed to maximize defrost effectiveness.  


  • Doesn’t depressurize livable space during the defrost cycle.  

  • Ideal for higher humidity outdoor conditions or colder outdoor conditions.  

Wall Controls with a TVOC Sensor

Dehumidistat and Sensor for IAQ


TVOC sensing controller, ECO-mode, w/o display, 4 wires

Optimizes FIT performance based on IAQ, indoor RH, and outdoor temperature
Maintains ventilation at RH level of 45%
20 mins ON/40 mins OFF per hour of operation at low speed
The ventilation rate increases when the IAQ sensor detects a spike in indoor air’s VOCs
Screenless design ideal for multi-family homes

ECO-Touch® IAQ

TVOC sensing controller, multi-function, display, 4 wires

Optimizes appliance performances based on IAQ, indoor RH, and outdoor temperature
Can be customized based on user preferences
Automatic operation in the ECO mode
Ventilation increases when the IAQ sensor detects a spike in indoor air's VOCs
The 3-leaf icon indicates the level of air quality
Touchscreen design perfect for high-end projects

Supporting Assets

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